runc: embed version from VERSION file

This ensures that if runc is built without the provided Makefile, the
version is still properly set.

No change in the output.

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

Makefile

@@ -17,8 +17,8 @@ BUILDTAGS += $(EXTRA_BUILDTAGS)
 
 COMMIT := $(shell git describe --dirty --long --always)
 EXTRA_VERSION :=
-VERSION := $(shell cat ./VERSION)$(EXTRA_VERSION)
-LDFLAGS_COMMON := -X main.gitCommit=$(COMMIT) -X main.version=$(VERSION)
+LDFLAGS_COMMON := -X main.gitCommit=$(COMMIT) \
+		  $(if $(strip $(EXTRA_VERSION)),-X main.extraVersion=$(EXTRA_VERSION),)
 
 GOARCH := $(shell $(GO) env GOARCH)
 
@@ -118,11 +118,11 @@ release: runcimage
 		--rm -v $(CURDIR):/go/src/$(PROJECT) \
 		-e RELEASE_ARGS=$(RELEASE_ARGS) \
 		$(RUNC_IMAGE) make localrelease
-	script/release_sign.sh -S $(GPG_KEYID) -r release/$(VERSION) -v $(VERSION)
+	script/release_sign.sh -S $(GPG_KEYID)
 
 .PHONY: localrelease
 localrelease: verify-changelog
-	script/release_build.sh -r release/$(VERSION) -v $(VERSION) $(RELEASE_ARGS)
+	script/release_build.sh $(RELEASE_ARGS)
 
 .PHONY: dbuild
 dbuild: runcimage

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	_ "embed"
 	"errors"
 	"fmt"
 	"io"
@@ -19,12 +20,18 @@ import (
 	"github.com/urfave/cli"
 )
 
-// version must be set from the contents of VERSION file by go build's
-// -X main.version= option in the Makefile.
-var version = "unknown"
+// version is set from the contents of VERSION file.
+//
+//go:embed VERSION
+var version string
+
+// extraVersion is an optional suffix appended to runc version.
+// It can be set via Makefile ("make EXTRA_VERSION=xxx") or by
+// adding -X main.extraVersion=xxx option to the go build command.
+var extraVersion = ""
 
 // gitCommit will be the hash that the binary was built from
-// and will be populated by the Makefile
+// and will be populated by the Makefile.
 var gitCommit = ""
 
 func printVersion(c *cli.Context) {
@@ -73,7 +80,7 @@ value for "bundle" is the current directory.`
 func main() {
 	app := cli.NewApp()
 	app.Name = "runc"
-	app.Version = version
+	app.Version = strings.TrimSpace(version) + extraVersion
 	app.Usage = usage
 
 	cli.VersionPrinter = printVersion